I start a project to study digital and it's been 4 months since I started with ANSYS13 FLUENT. (Figure 1)

I start by simulating the flow of blood through a vein with the presence of a probe (blood flow between two parallel cylinders) to validate my model.
The study is already done.
I can not find the correct profile (I found an acceleration along the cylinder) (figure 2), the rate does not stabilize. The flow is along the Z axis

Normally I have to find a profile such that the (figure 3)

The conditions I have are:
The vein is modeled by a straight cylinder of diameter D = 25.8mm and length L = 300mm. The probe is modeled by a right cylinder of diameter d = 3.1mm and the same length.
The flow area is S = pi (D ²-d ²) / 4 = 515.245mm ²